This invention is in the field of devices for removing solids from paint and in particular in the field of devices for straining solids from paint that would hinder the use of a paint sprayer.
At the time of manufacture, the pigment and other non-solvent constituents of paint, as well as contaminants, are typically in solution or suspended with a small particle size. As the paint subsequently sits in bulk storage containers and buckets in which the paint is distributed and sold, some of the solids tend to aggregate and settle out. A skim of solids may also form on the top of the paint. Attempts to break down these clumps into a small particle size and to re-suspend the solids through shaking the paint at the time of sale is usually not entirely successful. Furthermore, the paint may sit for days or longer after sale resulting in the aggregation or re-aggregation of more clumps. Attempts to break down the clumps and re-suspend the solids at the time of use by stirring or hand shaking also leads to a limited success. The result is that, at the time of use, paint usually will have clumps and other solids that will clog the intake screen of a paint sprayer, thereby resulting in lost time and lost productivity in the painting process.
A number of devices have been developed to deal with this problem, with varying degrees of success. Some of the prior art devices provide for screening of the paint as it is poured into the top of a receiving bucket. These devices are generally positioned on or affixed to the top rim of the receiving bucket. Each of these devices has a straining surface or screen which may range in configuration from a flat screen extending across the top of the receiving bucket, such as is disclosed in U.S. Pat. No. 5,059,319 to Welsh, or a bag shaped screen extending downwardly below the top of the straining device or below the top of the receiving bucket such as that disclosed in U.S. Pat. No. 6,247,600 B1 to Sullivan, U.S. Pat. No. 5,368,728 to Reaves, U.S. Pat. No. 5,186,828 to Mankin, U.S. Pat. No. 4,946,591 to Mealey, U.S. Pat. No. 4,804,470 to Calvillo et al., U.S. Pat. No. 2,250,646 to Metsch, U.S. Pat. No. 2,070,998 to Odom, U.S. Pat. No. 1,451,206 to Dow, U.S. Pat. No. 1,051,735 to Hammond, and U.S. Design Pat. No. 410,123 to Matarazzo et. al.
U.S. Pat. No. 1,590,572 to Fredette discloses a strainer cup for use with varnish.
U.S. Pat. No. 3,301,404 to Becker discloses a strainer that is held against the top of a paint bucket as it is tipped. The paint is poured from the bucket through the strainer into a receiving bucket, thereby straining out the solids.
U.S. Pat. No. 5,935,435 to Hasler and U.S. Pat. No. 6,149,808 to Johnson disclose cylindrical or cup shape strainers for inserting in a bucket of paint, providing for the straining of solids from the paint as it flows inwardly through the cylindrical strainer into the interior space of the strainer. The Hasler device provides for the pouring of paint from the interior of the cylinder. The Johnson device merely provides for the insertion of a brush or other painting implement into the interior of the cylinder where the strained paint is available.
While each of the foregoing devices achieves the principal objective, namely to remove unwanted solids from the paint, with some degree of success, each has some significant deficiencies. Each of the devices using a flat horizontal strainer affixed at the top of a receiving bucket or a bag shaped strainer mounted above or extending into the receiving bucket are mainly designed for batch use. That is, they are mounted on a receiving bucket, paint is poured in through the strainer into the receiving bucket and then the strainer is removed. The straining device must then be cleaned to prevent the paint from drying in place and stored for re-use, unless the strainer is intended for disposal after only one use. While the device disclosed by Sullivan does provide for a paint sprayer intake to be inserted into the reservoir of strained paint, with the strainer device remaining in place considerable strainer area is still exposed to drying as the paint is drawn down. The remaining devices disclosed by the patents identified above appear very ill suited for a continuous paint spraying operation. Further, these devices are generally expensive, cumbersome and time consuming to use. Most of them, from a practical standpoint, require either that they be disposable or that messy cleaning effort be made repeatedly to allow re-use of the screen. The devices providing for straining into an interior cup or cylinder shape strainer are particularly poorly suited for use with a continuous paint spraying operation.
A device is needed that provides for the reliable, economical and non-disruptive straining of paint that is readily compatible with a continuous paint spraying operation.
It is an objective of the present invention to provide a paint strainer that will provide for continuous straining of paint for a paint spraying operation.
It is a further objective of the present invention to provide a paint strainer which is economical.
It is a still further objective of the present invention to provide a paint strainer which is specifically designed for use with paint buckets which are commonly used by manufacturers for distributing and selling paint.
It is a still further objective of the present invention to provide a paint strainer which does not require frequent cleaning.
It is a still further objective of the present invention to provide a paint strainer that is easy to clean.
It is a still further objective of the present invention to provide a paint strainer which strains the paint as the paint flows from one side of the bucket to the other horizontally through the paint strainer.
The present invention is a paint strainer dimensioned to fit in a paint bucket, in a vertical position, snugly against the bottom and opposing sides of the paint bucket. The paint strainer fits in a vertical plane which passes through the center of the paint bucket, dividing the paint bucket into a receiving side and a strained paint side. The paint strainer has a strainer frame around the perimeter of the paint strainer which defines the bottom, sides and top of the paint strainer, and has a paint screen which is secured and sealed to the strainer frame. A pair of bucket top brackets, one affixed to the top of each side of the strainer frame, secures the paint strainer to the paint bucket.
Once the paint strainer is inserted into the paint bucket and secured in place by the bucket top brackets, paint is poured into the receiving side of the paint bucket and the paint flows through the paint strainer into the strained paint side of the paint bucket. This can continue until the paint bucket is full, with unstrained paint on the receiving side of the paint strainer and strained paint on the strained paint side of the paint strainer. A paint sprayer intake tube can then be inserted into the strained paint side for spray painting. As the paint on the strained paint side is drawn down, paint continues to flow from the receiving side through the paint strainer to the strained paint side. With periodic replenishment of the paint on the receiving side, the paint spraying operation can proceed more or less continuously, ordinarily without the necessity of removing and cleaning the paint strainer until the paint spraying operation is finished for the day.